The Notch Receptor and Its Ligands Are Selectively Expressed During Hematopoietic Development in the Mouse - Walker - 2001 -...
Members of the Notch family of transmembrane receptors are found on primitive hematopoietic precursors, and Notch ligand expression has been demonstrated on the surface of stromal cells, suggesting a role for Notch signaling in mammalian blood cell development. The current report examines the expression of Notch receptors and their ligands in murine hematopoietic tissues to determine: A) which blood cell lineages in the adult are influenced by Notch activity, and B) whether fetal hematopoiesis in the embryo involves the Notch pathway. In the adult mouse, a combination of flow cytometry, immunohistochemistry and Northern analysis was used to examine Notch receptor or ligand expression in bone marrow and spleen. In the embryo, Northern analysis and in situ hybridization were used to characterize Notch receptor ...http://onlinelibrary.wiley.com/doi/10.1634/stemcells.19-6-543/abstract
The Tumor Suppressor Ikaros Shapes the Repertoire of Notch Target Genes in T Cells | Science Signaling
The Notch signaling pathway is activated in many cell types, but its effects are cell type- and stage-specific. In the immune system, Notch activity is required for the differentiation of T cell progenitors, but it is reduced in more mature thymocytes, in which Notch is oncogenic. Studies based on single-gene models have suggested that the tumor suppressor protein Ikaros plays an important role in repressing the transcription of Notch target genes. We used genome-wide analyses, including chromatin immunoprecipitation sequencing, to identify genes controlled by Notch and Ikaros in gain- and loss-of-function experiments. We found that Ikaros bound to and directly repressed the expression of most genes that are activated by Notch. Specific deletion of Ikaros in thymocytes led to the persistent expression of Notch target genes that are essential for T cell maturation, as well as the rapid ...http://stke.sciencemag.org/content/7/317/ra28
"Critical role of endothelial Notch1 signaling in postnatal angiogenesi" by K Takeshita, M Satoh et al.
Notch receptors are important mediators of cell fate during embryogenesis, but their role in adult physiology, particularly in postnatal angiogenesis, remains unknown. Of the Notch receptors, only Notch1 and Notch4 are expressed in vascular endothelial cells. Here we show that blood flow recovery and postnatal neovascularization in response to hindlimb ischemia in haploinsufficient global or endothelial-specific Notch1(+/-) mice, but not Notch4(-/-) mice, were impaired compared with wild-type mice. The expression of vascular endothelial growth factor (VEGF) in response to ischemia was comparable between wild-type and Notch mutant mice, suggesting that Notch1 is downstream of VEGF signaling. Treatment of endothelial cells with VEGF increases presenilin proteolytic processing, gamma-secretase activity, Notch1 ...https://mouseion.jax.org/stfb2000_2009/1488/
RIPping Notch Apart: A New Role for Endocytosis in Signal Transduction? | Science Signaling
Notch proteins are receptors that are important in mediating several developmental processes. Notch receptors are activated upon binding transmembrane ligands, the DSL proteins. Notch is cleaved at several sites and activation of Notch leads to the cleavage of the intracellular domain, which then is translocated to the nucleus and regulates the transcription of target genes. Krämer discusses how binding of Notch to the DSL ligand, Delta, leads to cleavage and trans-endocytosis of the Notch extracellular domain into the Delta-expressing cell. This trans-endocytosis event contributes to the cleavage and release of the active Notch intracellular domain. The Perspective is accompanied by a movie illustrating the trans-endocytosis of Notch.. ...http://stke.sciencemag.org/content/2000/29/pe1
Enhancement of Notch Receptor Maturation and Signaling Sensitivity by Cripto-1
coreceptor Cripto-1. Coimmunoprecipitation analysis confirmed the binding of Cripto-1 with all four mammalian Notch receptors. Deletion analyses revealed that the binding of Cripto-1 and Notch1 is mediated by the Cripto-1/FRL-1/Cryptic domain of Cripto-1 and the C-terminal region of epidermal growth factor-like repeats of Notch1. Binding of Cripto-1 to Notch1 occurred mainly in the endoplasmic reticulum-Golgi network. Cripto-1 expression resulted in the recruitment of Notch1 protein into lipid raft microdomains and enhancement of the furin-like protein convertase-mediated proteolytic maturation of Notch1(S1 cleavage). Enhanced S1 cleavage resulted in the sensitization to ligand-induced activation of Notch signaling ...https://dash.harvard.edu/handle/1/4621598
"Endocytic Regulation of Notch Signaling in Drosophila Melanogaster Neu" by Seth Andrew Johnson
Notch signaling is a ubiquitously used signaling pathway that is highly conserved and used throughout metazoan development. Understanding the regulation of Notch signaling is becoming increasingly important in determining the mechanism and treatment for the myriad of human Notch-related diseases. In Drosophila. melanogaster, the development of external sensory organs provides a context in which Notch can be manipulated and phenotypes can be easily interpreted. Here, we expand upon the growing field of Notch regulation through endocytic trafficking by examining the role of Numb and Sara endosomes. Numb is a potent Notch inhibitor whose function is conserved in higher organisms, but whose mechanism of action has remained elusive. In this study, we dispel a previous hypothesis that Numb promotes Notch internalization and instead demonstrate that Numb is a suppressor of Notch ...https://repository.upenn.edu/edissertations/1790/
Sugar-coating Notch | Science Signaling
Notch is a transmembrane receptor for the transmembrane ligands Delta and Jagged (also known as Serrate). Signaling by Notch is important for establishing boundaries during development (see accompanying article by Fortini). Fringe modifies Notch signaling when expressed in Notch-expressing cells. Two groups, Brückner et al. and Moloney et al., show that Fringe is a glycosyltransferase that catalyzes the elongation of O-linked fucose residues on the epidermal growth factor repeats of the Notch receptor. Brückner et al. show that coexpression of Fringe and Notch enhances the interaction between Notch and Delta and that the glycosyltransferase activity of Fringe is essential for this activity. Moloney et al. show that when Notch is modified by Fringe, activation of Notch by Jagged1 is inhibited. Thus, carbohydrate modification ...http://stke.sciencemag.org/content/2000/43/tw1
A Functional Analysis of Notch Mutations in Drosophila | Genetics
The Notch gene encodes a receptor protein that is involved in many processes during development. Its best understood role is during neurogenesis in a process called "lateral inhibition." However, it has been proposed that Notch also has a role in defining the proneural clusters in the first place. This raises the possibility that the Notch protein is acting as a multifunctional receptor. To test this hypothesis, we have carried out a genetic analysis of molecularly characterized Notch alleles to identify alleles that affect only one of the two proposed functions. Here we present evidence that Notch alleles can be identified that appear to affect the function of Notch during either lateral inhibition or the definition of proneural clusters. In addition our results indicate that there may be discrete regions of the Notch protein required for each function.. ...http://www.genetics.org/content/147/1/177?ijkey=4a317b190b939ffbe3f1c3cf278f61f550fa627e&keytype2=tf_ipsecsha
Notch Activation by Dll1 Simulation Induces Drug Resistance in Multiple Myeloma | Current Science
Drug resistance is one of the major problems in multiple myeloma (MM) clinical treatment. It is reported that Notch pathway was involved in drug resistance. In this study, we demonstrated that Notch activation by Dll1 simulation could induce drug resistance to bortezomib in murine and human MM cells. Blocking Notch pathway by DAPT (Notch inhibitor) could reverse the effect and increased the sensitivity to bortezomib. Notch activation decreased the cell apoptosis which was induced by bortezomib treatment as measured by flow cytometry. Further investigation showed that Dll1 simulation could down-regulate CD138, Blimp-1 and XBP-1 mRNA expression and shifts MM cells to a more resistant CD138- phenotype with a significant increase of CD138- subpopulation as detected by flow cytometry both in murine and human MM cells. Meanwhile, by MACS and FACS sorting of CD138+ subpopulation, we found that Notch activation ...http://currentscience.org/index.php/CS/article/view/142
Eya1 controls cell polarity, spindle orientation, cell fate and Notch signaling in distal embryonic lung epithelium |...
Notch signaling is used for cell fate determination throughout the animal kingdom, and differences in Notch activity between two daughter cells determine their future fates. Thus, Notch signaling promotes progenitor cell identity at the expense of differentiated cell phenotypes (Jadhav et al., 2006; Mizutani et al., 2007). Differences in the Notch activities between two daughter cells can be specified by the asymmetric localization and inheritance of Numb, a negative regulator of the Notch pathway (Guo et al., 1996; Cayouette et al., 2001; Petersen et al., 2002; Shen et al., 2002). In the embryonic lung, Notch signaling controls cell fates in developing airways (Post et al., 2000; Tsao et al., 2008; Tsao et al., 2009), and Notch activation inhibits the differentiation of distal progenitors into alveolar cells (Guseh et al., 2009). Yet the role of asymmetric segregation of cell fate ...http://dev.biologists.org/content/138/7/1395
Leicester Research Archive: Notch3 and HEY-1 as prognostic biomarkers in pancreatic adenocarcinoma
In order to achieve a better outcome for pancreatic cancer patients, reliable biomarkers are required which allow for improved diagnosis. These may emanate from a more detailed molecular understanding of the aggressive nature of this disease. Having previously reported that Notch3 activation appeared to be associated with more aggressive disease, we have now examined components of this pathway (Notch1, Notch3, Notch4, HES-1, HEY-1) in more detail in resectable (n = 42) and non-resectable (n = 50) tumours compared to uninvolved pancreas. All three Notch family members were significantly elevated in tumour tissue, compared to uninvolved pancreas, with expression maintained within matched lymph node metastases. Furthermore, significantly higher nuclear expression of Notch1, -3 and -4, HES-1, and HEY-1 (all p ≤ 0.001) was noted in locally advanced and metastatic tumours compared to resectable cancers. In ...https://lra.le.ac.uk/handle/2381/37313
Endosomal sorting of Notch receptors through COMMD9-dependent pathways modulates Notch signaling | JCB
This study sheds light into a previously unappreciated role for COMMD9 in vesicular sorting and the delivery of Notch proteins to the cell surface. Absent COMMD9, Notch is mislocalized in intracellular early endosomes, and the response to Notch ligands is substantially attenuated. Furthermore, our studies indicate that Notch is not only mislocalized but also undergoes lysosomal degradation. Interestingly, we found that similar phenotypes are observed in cells deficient in CCC components CCDC93 and C16orf62 and the retromer subunit VPS35. This latter complex, which is critically important for the endosomal recycling of a large number of receptors (Seaman et al., 2013), has not been previously linked to Notch trafficking (Steinberg et al., 2013).. The observation that COMMD9-dependent effects on Notch trafficking can dramatically affect signaling is in line with a large body of literature that ...http://jcb.rupress.org/content/211/3/605
As a previous work has suggested the potential for cross-talk between the Notch and Hedgehog signaling cascades (14), we focused on the upregulation of Hedgehog signaling in response to MRK-003. Increased levels of Notch pathway components are seen in Hedgehog-driven medulloblastoma models (15, 42) and it was initially suggested that these tumors may be dependent on Notch signaling for survival (15). More recent studies, however, indicate that Hedgehog-driven medulloblastomas can grow in the absence of canonical Notch activity (43, 44). Additionally, several groups have demonstrated that Hedgehog pathway components Gli1 and Gli2 are able to positively regulate Hes1 independently of Notch (45, 46). However, when we treated several GBM neurosphere lines with the Hedgehog inhibitor cyclopamine we did not observe decreases in Hes1 or other Notch pathway targets, suggesting that Hedgehog does not play a ...http://clincancerres.aacrjournals.org/content/16/24/6060
Abstract 304: Notch Signaling in Coronary Arteries: Notch Ligand Delta-like1 Regulates Coronary Artery Numbers and is...
Introduction: Notch ligands of the Delta-like (Dll) family regulate embryonic and postnatal arteriogenesis. However, the role of notch signaling in coronary arteries, especially in the endothelium, is poorly characterized. We have analyzed the role of Notch ligand Dll1 in coronary arteries and myocardial infarction.. Methods and Results: Analysis of Dll1 expression by immunofluorescence and Dll1-lacZ reporter gene studies in adult mouse hearts revealed selective endocardial and coronary endothelial, but not venous or capillary Dll1 expression. Hearts of mice heterozygous for Dll1 (Dll1+/−) were significantly smaller than wildtype (wt) hearts (heart weight (g)/femur length (cm), wt: 0.13± 0.02 vs. het: 0.09± 0.02, n=10, p,0.05) while body weight and survival over 18 months was comparable. Furthermore, the number of medium (,50 -100 um) and large (,100 um) coronary arteries was significantly reduced in Dll1+/− hearts (p,0.01). Reduced coronary numbers were ...http://circ.ahajournals.org/content/116/Suppl_16/II_42.3
Delta-Like 4 Induces Notch Signaling in Macrophages | Circulation
The present study affirms our hypothesis that the Notch pathway plays an important role in macrophages, a key cell type in inflammation and atherosclerosis. Evidence that supports this idea includes the expression of multiple Notch receptors and ligands in human macrophages; markedly increased Dll4 expression in human macrophages stimulated with LPS, mmLDL, or IL-1β, an event that likely involves TLR4 and NF-κB; the ability of Dll4 to bind to macrophages and trigger Notch signaling; the induction of the MAPK, Akt, and NF-κB pathways in macrophages stimulated with Dll4; the Dll4-induced transcription of iNOS, PTX3, Id1, and Dll4 itself; and the presence of Notch pathway components, such as Dll4 and Notch3, in human atherosclerotic plaques rich in macrophages.. Dll4 expression induced in human primary macrophages by proinflammatory stimuli (LPS, IL-1β, and mmLDL) (Figures 2 through 4⇑⇑) and the detection of ...http://circ.ahajournals.org/content/115/23/2948.long
"The Role of Notch Signaling in Vascular Remodeling " by Sarah Maier Peterson
Following injury, smooth muscle cells in the wall of the blood vessel can switch from a quiescent, contractile phenotype to a migratory, proliferative phenotype which contributes to lesion formation and vascular occlusive disease. Important regulators of vascular smooth muscle cell phenotype include serum response factor and its cofactor myocardin, growth factors, Krüppel-like factors, microRNA-143/145 and Notch signaling. The Notch signaling pathway is highly conserved and plays a critical role in both vascular development and disease. In mammals, there are five Notch ligands (Jagged1, Jagged2, Delta-like 1, Delta-like 3, and Delta-like 4) and four Notch receptors (Notch1-4). Knockout mouse models of most of the Notch ligand and receptor components display early embryonic lethality due to abnormal vasculogenesis, indicating their essential role in cardiovascular ...https://digitalcommons.library.umaine.edu/etd/2361/
Notch signaling regulates gastric antral LGR5 stem cell function | The EMBO Journal
Here we report that Notch signaling controls gastric epithelial cell homeostasis by regulating antral stem cell function. Our lineage tracing studies in adult NIP1::CreERT2 mice showed that antral stem cells are actively signaling from the Notch1 receptor, thus demonstrating that the Notch pathway directly targets these cells under normal homeostatic conditions. Manipulation of Notch signaling showed that Notch functions to promote overall stem cell proliferation. Blocking Notch by pharmacologic or genetic means reduced stem cell proliferation, while genetic activation of Notch signaling in LGR5+ stem cells increased the number of proliferating stem cells. Expression of the Notch target gene Olfm4 paralleled the changes in stem cell proliferation, suggesting that it may be an antral stem cell marker, similar to what has been reported for LGR5+ stem cells in ...http://emboj.embopress.org/content/early/2015/08/12/embj.201490583
High expression of Notch-1 and/or Jagged-1 has negative prognostic significance in breast cancer ( 14, 15), and Notch-1 can transform HMECs ( 16). Our data confirm that Notch-1 and Notch-4 are commonly coexpressed in infiltrating breast cancers of ductal and lobular histologies, which also express Notch ligands Jagged-1 and Delta-1. However, our observations on breast cancer cell lines suggest that there may not be a simple correlation between protein levels of Notch receptor and ligands and Notch pathway activity level. Our data suggest that estrogen inhibits Notch signaling through an ERα-dependent effect, which is at least in part mediated by inhibition of Notch cleavage by γ-secretase. Inhibition of Notch activation by estrogen is observed under physiologic, ligand-induced Notch activation conditions, ...http://cancerres.aacrjournals.org/content/68/13/5226
Molecular Pathways: Context-Dependent Approaches to Notch Targeting as Cancer Therapy | Clinical Cancer Research
Specific functional consequences of mutated Notch receptors and ligands are largely not yet experimentally defined, but the clustering of mutations in known functional elements invites speculation with regard to whether the specific Notch receptor likely functions as a tumor suppressor or oncogene in a specific cancer type (Fig. 2).. More NOTCH1 gene mutations were observed than mutations in the other NOTCH receptor genes. This was in part, but not entirely, due to the greater number of tumors with NOTCH1 sequencing data. For HNSCC, lung SCC, and breast, NOTCH1 mutations were relatively frequent, with 5% to 15% of tumors harboring protein coding changes. Many of these missense mutations occurred at or near identified important domains such as the ligand-binding domain (EGF repeats 11 and 12) or the ankyrin domains (Fig. 2). Nonsense mutations observed in ...http://clincancerres.aacrjournals.org/content/18/19/5188.long
"Distinct Notch signaling outputs pattern the developing arterial syste" by Aurelie Quillien, John C. Moore et al.
Differentiation of arteries and veins is essential for the development of a functional circulatory system. In vertebrate embryos, genetic manipulation of Notch signaling has demonstrated the importance of this pathway in driving artery endothelial cell differentiation. However, when and where Notch activation occurs to affect endothelial cell fate is less clear. Using transgenic zebrafish bearing a Notch-responsive reporter, we demonstrate that Notch is activated in endothelial progenitors during vasculogenesis prior to blood vessel morphogenesis and is maintained in arterial endothelial cells throughout larval stages. Furthermore, we find that endothelial progenitors in which Notch is activated are committed to a dorsal aorta fate. Interestingly, some arterial endothelial cells subsequently downregulate Notch signaling and then contribute to veins during vascular remodeling. Lineage analysis, together with ...http://escholarship.umassmed.edu/gsbs_sp/1915/
Ligand-dependent Notch signaling strength orchestrates lateral induction and lateral inhibition in the developing inner ear |...
During inner ear development, Notch exhibits two modes of operation: lateral induction, which is associated with prosensory specification, and lateral inhibition, which is involved in hair cell determination. These mechanisms depend respectively on two different ligands, jagged 1 (Jag1) and delta 1 (Dl1), that rely on a common signaling cascade initiated after Notch activation. In the chicken otocyst, expression of Jag1 and the Notch target Hey1 correlates well with lateral induction, whereas both Jag1 and Dl1 are expressed during lateral inhibition, as are Notch targets Hey1 and Hes5. Here, we show that Jag1 drives lower levels of Notch activity than Dl1, which results in the differential expression of Hey1 and Hes5. In addition, Jag1 interferes with the ability of Dl1 to elicit high levels of Notch activity. Modeling the sensory epithelium when the two ligands are expressed together shows that ligand ...http://dev.biologists.org/content/early/2014/05/12/dev.108100
Enhancement of Notch receptor maturation and signaling sensitivity by Cripto-1 | JCB
A recent study has shown that Cr-1 controls processing of the Nodal proprotein by recruiting proprotein convertases such as furin or PACE4 (Blanchet et al., 2008). Because processing by furin-like convertases (S1 cleavage) is also a prerequisite to generate mature heterodimerized Notch receptors (Logeat et al., 1998), we hypothesized that CR-1 may affect this processing step. Similar to the sequestration of the Nodal precursor protein into lipid rafts (Blanchet et al., 2008), forced expression of CR-1 in CR-1-deficient CHO cells enhanced the localization of the FL Notch1 protein in the lipid raft fraction in which glycosylphosphatidylinositol-anchored proteins such as CR-1 are enriched (Fig. 4 B). Furthermore, we assessed the effect of CR-1 expression on S1 cleavage of Notch1 in the presence of the γ-secretase inhibitor DAPT to exclude the effect on ligand-induced S3 cleavage (Fig. 4, C and D). CR-1 expression caused a dose-dependent ...http://jcb.rupress.org/content/187/3/343
Notch Inhibitor DAPT Blocks Fibroblastic Transformation of Corneal Endothelium | IOVS | ARVO Journals
Purpose: : To explore the role of Notch signaling in corneal endothelial-mesenchymal transformation (EnMT). Methods: : EnMT was induced in rat corneal endothelial cells (RCECs) by serial passages or TGF-β treatment, with or without 10µM DAPT. Cell phenotype and transformation were evaluated by EnMT markers, growth curve, scratch test, immunostaining and RT-qPCR. An in vivo EnMT rat model was induced by transcorneal freezing, with or without topical treatment of 50µM DAPT for 14 days. The wound endothelium was evaluated by slit lamp, stereomicroscope, immunostaining and RT-qPCR. Results: : Corneal EnMT in vitro was evidenced by changed morphology, downregulated tight junctions (ZO-1, Cx43 and N-cadherin), increased α-SMA and Notch signaling (Notch1, Notch2, Jag1 and Hes1). DAPT blocked EnMT induction, also reversed the phenotype, morphology and hyperplasia of the transformed RCECs. In rat, DAPT treatment blocked the EnMT process, with normal ...http://iovs.arvojournals.org/article.aspx?articleid=2359706
The NOTCH signaling pathway is evolutionally conserved and critical in stem cell differentiation and cell fate determination in development. Its roles in malignant initiation and progression, however, are complex and appear organ/cell-type dependent.. Four NOTCH receptors (NOTCH 1-4) exist in mammals with a different number of EGF-like repeats and are activated upon binding to ligands (1). The activation requires two sequential protein cleavage steps by ADAM10/17 metalloproteases and presenilin-γ-secretase complex (γ-secretase) to release the intracellular portion of the NOTCH, also known as ICN, which is translocated into the nucleus and mediates activation of the NOTCH pathway (2-4). Therefore, NOTCH pathway activities can be impacted by not only NOTCH receptors themselves but also their ligands, the protein cleavage steps, and ICN nuclear translocation.. ...http://cancerpreventionresearch.aacrjournals.org/content/8/4/259
Abstract 13219: Dll4-Notch Signaling Mediates Vascular Inflammation and Calcification in Chronic Kidney Disease: A Novel...
Background: Chronic kidney disease (CKD) increases cardiovascular risk. However, the underlying mechanisms remain obscure and current therapies, including statins, cannot prevent CKD-associated cardiovascular events. We previously demonstrated that the Notch signaling ligand Delta-like 4 (Dll4) promotes macrophage activation. To identify a new mechanism and therapeutic target, we investigated the causal role of the Dll4-Notch pathway in vascular inflammation in CKD.. Methods & Results: [In vitro] Indoxyl sulfate, a major uremic toxin, is an independent risk predictor in CKD. Clinically relevant concentrations (0.5-1.0 mM) of indoxyl sulfate increased the expression of proinflammatory molecules (e.g., IL-1β, TNFα, MCP-1), and Notch signaling components (e.g., Dll4, Notch3) in human primary macrophages derived from peripheral blood mononuclear cells. Notch inhibition with the γ-Secretase inhibitor DAPT suppressed indoxyl ...http://circ.ahajournals.org/content/132/Suppl_3/A13219